Transmission-gear.



No. 772,348. PATENTBD OCT. 18, 1904. A. J. FARNSWORTH.

TRANSMISSION GEAR.

APPLICATION FILED mum. 1903.

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A. J. FARNSWORTH.

TRANSMISSION GEAR.

. APPLIOATION IILED rn'B'. 5. 1903.

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PATENT OFFICE.

ARTHUR J. FARNSVVORTH, OF NEW YORK, N. Y., ASSIGNOR TO RAILWAY ELECTRICAL IMPROVEMENT COMPANY, OF NEW YORK, N. Y., A COR- PORATION OF NEW JERSEY.

TRANSMISSION-GEAR.

SPECIFICATION forming part of Letters Patent N0. 772,348, dated October 18, 1904.

I Application filed February 5, 1903. Serial No. 142,080- (No model.) i

To all whom, it may concern:

Be it known that I, ARTHUR J. FARNSWORTH, acitizen of the United States, residing at New York, in the county of New York and State of New York, have invented an Improvement in Transmission-Gear, of which thefollowing description, in connection with the accompanying drawings, is a specification, like letters on the drawings representing like parts.

My invention consists in improvements in transmission-gears, and particularly in transmissiongears intended to transmit motion from a driving to a driven member where the driving member has a variable position relative to the driven member, as in the case of a car-lighting system employing an axle-driven dynamo. v

My invention will be best understood from the following description and accompanying illustrations of one specific embodiment thereof, while its scope will be particularly pointed out in the appended claims.

Referring to the drawings, Figure 1 is an elevation, partially in section, showing one 2 5 specific embodiment or form of my invention. Fig. 2 is a detail illustrative thereof. Fig. 3 is a sectional elevation taken on the line 3 3, Fig. 4, showing the employment of one form of my improved transmission-gear in driving 0 an electric generator from the car-axle of a railway-car, the latter being only partially shown; and Fig. lis a plan view of the structure shown in Fig. 3.

In the drawings, referring to Fig. 1 and to 3 5 the specific embodiment of my invention illustrated therein, a is a driving-shaft from which movement is communicated to a driven shaft 6, the latter being fixed in position and herein laterally disposed with respect to the driving- 4 shaft a, which is subject to a substantially vertical displacement above or below its normal or full-line position, as indicated in Fig. lbydotted lines. A driving-gear c is keyed or otherwise fixedly secured to the driving-shaft and drives the pinion d upon the driven shaft, in the present instance through engagement with the intermediate gear 6 upon-the shaft f. It will be evident that if the shaft f were fixedly secured in position relative to the shaft 6 each vertical movement or displacement without rotation of the shaft (0 with its drivinggear a in an upward direction would cause a corresponding angular displacement of the gear 6, imparting to the latter a right-hand angular movement and to the gear d a corresponding left-hand angular movement. downward displacement of the shaft a would cause a similar angular movement to be imparted to the gear d and the shaft 5 in an opposite direction. Any vertical displacement of the shaft (0 while the latter is rotating and transmitting motion to the shaft 6 would cause momentary acceleration or retardation of the speed of rotation of shaft Z) and a consequent deviation from the correct angular movement which should be transmitted from the driving to the driven shaft, and if such vertical displacement of shaft (0 were sudden the effect upon the driven gear d would be that of a sharp blow in one direction or the other. v

In the form of my invention illustrated in Fig. l I have so arranged the intermediate gear 6 that it also undergoes a linear displacement with the gear 0; but its center is constrained to move along its path in such a way that any displacement of the same due to the displacement of shafta without rotation causes no angular movement in the gear d. To this end I support the shaft f, carrying the-idle gear, in bearings carried by the arm or link g, the latter having a bearing upon the shaft a, with which it moves upwardly or downwardly about a supportingpivot 71, the armg having a slightly-elongated eye or opening to receive the pivot h and allow for its slight lateral movement upon the latter.

of the shaft (6. As the shaft (6 moves upward each tooth upon the gear undergoes a corresponding upward movement, and those teeth in engagement with the teeth on gear 0 give to the latter a bodily movement substantially twice the movement of the center of gear 6. Gear 0 therefore has a combined angular and linear movement, the angular movement being correctly proportioned to produce an effect, so far as the transmission of movement is concerned, as if the pitch-circle of gear 0 had rolled along a vertical plane surface without slipping upon the same, the actual effect being that the teeth of gear 6 merely roll or slide over the teeth of gear (Z without imparting to the latter any angular change of position. The lateral displacement of gear 6 pro duces, of course, in the particular form shown a variation in the distance between the gear centers of eand d. Although this distance variation may often be negligible with any form of gearing Where the displacement of the driving-shaft is not excessive, in practice, however, I prefer to employ involute gears which have the property of running correctly at any distance between centers, and the variations of this distance will only affect the variation in the backlash between the engaging gears. It will be evident that in the construction which I have described the transmission -gear transmits absolutely and correctly all angular motion from the drivingshaft (0 to the driven shaft 6 and that any lateral displacement of shaft a and its drivinggear 0 cannot affect the driven gear (Z nor cause any variation in the angular velocity of the latter.

In Fig. 1 I have shown in dotted lines the position which will be assumed by the gears c and 0 when the shaft (4 undergoes a vertical upward displacement in moving from the normal or full-line position, the angular position of the shaft 6 and its gear being assumed to have undergone no change. The gear 0 is thereby given an angular movement so related to the linear movement of the gear center as to cause the teeth on the same to roll or slide idly over the teeth on gear (Z Without causing any change in the angular position of the latter. The relative positions of the teeth on gear 6 in engagement with d before and after the combined linear and angular movement of the former will be seen by referring to the enlarged detail view of the same shown in Fig. 2. It will also be evident that a down ward displacement of shaft (0 will have no further effect upon the angular velocity of gear d than an upward displacement and that as the shaft (0 moves upward or downward, whether suddenly or slowly and whether with or without angular movement, the only effect is to cause the teeth on the gear a to roll or slide idly over the teeth on the gear (Z. It is also to be noted that while I have assumed and described the shaft a to be the driving and the shaft t the driven shaft the transmissiongear is reversible and may be employed to transmit power from a shaft of variable position to one that is stationary, or vice versa. It will of course be obvious that the relative as well as actual dimensions of the gears may be varied as desired and that these may assume any proportions which the desired ratio of gearing or other considerations require.

\Vhile I have shown the pivotal or oscillatory supports for the link g located at one point concentric with the car-axle and at another at one side of the gear (Z, these locations may be elsewhere and are here selected for convenience only.

Referring to Figs. 3 and 4:, I have illustrated therein the manner in which the gear -'shown in Fig. 1 may be usefully employed in transmitting power from the axle of a railway car to an electric generator mounted upon the truck of the car and employed for lighting or other desired purpose. The generator I preferably secure upon any suitable portion of the car-truck frame, which isherein conveniently represented as by bolting the same to the cross-struts or transverse straps j, suitably secured to the longitudinal frame members it, although the generator may be mounted in any desired manner. The caraXle a, from which rotation is to be communicated to the generator, is provided with a driving-gear 0, which engages the intermediate gear e, supported in bearings carried by the links g. The latter have bearings upon the axle a and are supported at their opposite ends by the pin b, about which they may oscillate as the car-axle undergoes its upward or downward displacement relatively to the frame of the truck, carrying with them in their oscillations the intermediate gear 6. Angular motion is imparted from the gear 6 to the armature-shaft through the armaturepinion (Z. Since the distance from the center of the car-axle to the pin it is substantially twice that between the center of the gear a and the pin it, the vertical displacement of axle a, which, owing to switches, crossings, low joints, &c., occurs with great frequency and suddenness when the car is running, causes a corresponding substantially -evertical linear displacement of the geareof aboitlialf the amount of that of gear 0; but the teeth of the former merely roll or slide upon the teeth of the armature-pinion (Z without affecting the angular velocity of the latter or transmitting any shock to the same, and no matter how sudden or frequent or severe are the up and down movements of the car-axle the angular velocity of the latter will always be correctly transmitted to the armature-shaft without fluctuation or variation other than that due to corresponding fluctuations or variations in the angular velocity of the axle itself. In transmission-gears which have heretofore been employed for similar purposes displacegenerator is employed for lighting purposes, sudden changes in the angular velocity of the armature resulting from such displacements of the axle cause fluctuations in the voltage and in the intensity of the light produced.

With the transmission-gear which I have described these troubles are avoided and the generator-armature runs smoothly without fluctuations or shocks It will also be obvious that the gear which I have herein shown applied tothe specific purpose indicated is adapted for employment in a great variety of situations, and it will also be obvious to those skilled in the art that many modifications in the details of the. parts themselves and in their relation to each other 'and in their assemblage as a whole maybe made without departing from the spirit and scope of my invention, which is herein described with reference to the foregoing specific embodiment submitted for illustrative purposes only.

I claim 1. In a car-lighting system-employing an axle-driven electric generator, a driving-gear driven froma car-axle, a driven gear to drive said generator, said driving and driven gears being subject to displacement relatively to each other on displacement of the car-axlerelatively to the truck-frame, and means for transmitting the correct angular movement of the driving-gear to the driven gear irrespective of their relative displacement.

,2. In a car-lighting system employing an axle-driven electric generator, a driving-gear driven from a cal-axle, a driven gear to drive said generator, said driving and driven gears being subject to displacement relatively to each other on displacement of the car-axle relatively to the truck-frame, and means for preventing angular displacement of the driven gear when said gears are relatively displaced.

8. The combination in a car, of a car-axle, a shaft upon said car subject to displacement relatively to the car-axle during the movement of the car, a driving and a driven gear fortransmission of power between said shaft and said axle, said gears being subject to relative mit to the driven gear the correct driving effort only irrespective of said displacement.

4:. A power-transmission system having a driven and a driving gear subject to relative displacement and intermediate gearing subject also to displacement on the relative displacement of the driving and driven gears, said intermediate gearing havinga lineal body movement so related to the angular movement resulting from the displacement as to transmit to the driven gear the correct driving effort only irrespective of saiddisplacement.

5. In a car-lighting system, acar-truck, an electric generator rigidly supported thereon, a car-axle, and positive intermeshing driving means between said axle and generator comprising a driving-gear upon the car-axle, and a driven gear for driving said generator geared to said driving-gear.

6. The combination of a car-truck, a caraxle, adriving-gear driven from said car-axle, a driven gear, said driving and driven gears being subject to displacement relatively to each other on displacement of the car-axle relatively to the truck-frame, and means for preventing angular displacementof the driven gear when said gears are relatively displaced.

7. In a power-transmission system a driving and driven member subject to relative displacement and power-transmission means between the same for transmitting thecorrect angular movement of the driving member to thedriven member irrespective of their relative displacement.

8. The combination of a car-truck, a caraxle, a driving-gear driven from said car-axle, a driven gear, said driving and driven gears being subject to displacement relatively to each other on displacement of the car-axle relatively to the truck-frame, and a shiftable intermediate gear supported at two points, one of which is fixed relatively to the drivinggear and the other relatively to the driven gear.

9. The combination of a car-truck, a car axle, a'driving-gear mounted on said car-axle, a driven gear, an intermediate gear engaging both said driving and driven gears. a link to carry said intermediate gear, said link being swingingly mounted at one end on said caraxle and pivotally secured at its other end at a point fixed relatively to said driven gear.

10. The combination of a car-truck, a caraxle,a driving-gear driven from the car-axle, a driven gear, said driving and driven gears being subject to displacement relatively to each other on displacement'of the car-axle relatively to the truck-frame, a link pivotally mounted at two points, one fixed relatively to the driving-gear and the other relatively to the driven gear, and a gear intermediate said driving and driven gears supported by said link at a point substantially midway between its pivotal supports.

11. A transmission-gear for transmitting movement between two shafts subject to lateral displacements relatively to each other, comprising a driving-gear upon one shaft, a driven gear upon the other, and a gear intermediate said driving and driven gears supported midway between a point fixed relatively to the driving-gear and another point fixed relatively to the driven gear.

12. The combination of a car-truck, a carax'le, a driving-gear driven from the car-axle, a driven gear, said driving and driven gears being subject to displacement relatively to each other on displacement of the car-axle relatively to the truckframe, and a gear intermediate said driving and driven gears supported midway between a point fixed relatively to the driving-gear and another point fixed relatively to the driven gear.

13; The combination in a vehicle of a vehiole-axle, a shaft upon said vehicle subject to displacement relatively to the vehicle-axle du ring the movement of the vehicle, a driving and a driven gear for the transmission of power between said shaft and said axle; said gears being subjected to relative displacement similar to that of the said axle and shaft, and means for transmitting the correct angular movement of the driving-gear to the driven gear irrespective of their relative displacement.

14L. In a power-transmission system a driving and a driven member subject to relative displacement, and positive intcrmeshing cle-axle, a shaft upon said vehicle, said axle and shaft being subject to relative displacement during the vehicle movement; a driving and a driven gear for transmitting power between said shaft and axle, said gears being also subject to like relative displacement, and

intermediate transmitting means supported between two points, one fixed relative to the driving-gear, and the other to the driven gear for transmitting the correct angular movement of the driving-gear to the driven gear irrespective of their relative displacement.

- 16. An electric car-lighting system comprising an axle-driven generator receiving support upon the car-truck and independently of the axle, and means for transmitting from the axle to the generator or other power-consuming device employed correct angular movement in dependent of the displacement of said axle relatively to said truck.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses. 1

ARTHUR J FARNSWORTH. WVitnesses:

ERNEST P. HOES, WM. M. FISCHER. 

